RE: strong 25
Actually I am putting this 25 in a 15 size plane. It is an older one, you may remember it. Years ago they came out with a Birdie 40 and Birdie 15. I built them both. Very strong construction. Flew the Birdie 15 with an OS 15 in it and it flew ok but was under powered. I'm thinking a strong 25 will really make it scream. The tt36 might be too much for the 15 size plane. I'll talk about the 40 another day.